It could just be your DNS, I’ve had problems with Cloudflare’s 1.1.1.1 and Catbox but I think they actually have a list of ISPs and DNS providers that give them issues. I don’t think you can manually specify a DNS server on cellular (without some weird workaround), but if you have issues on other networks you can try changing your DNS and see what happens.
It could just be your DNS, I’ve had problems with Cloudflare’s 1.1.1.1 and Catbox but I think they actually have a list of ISPs and DNS providers that give them issues. I don’t think you can manually specify a DNS server on cellular (without some weird workaround), but if you have issues on other networks you can try changing your DNS and see what happens.